To reduce overall power consumption of a liquid crystal display and increase its contrast, backlight adjustment technology has been applied in the field of liquid crystal display.
At present, backlight adjustment of a liquid crystal display is achieved by local dimming. Specifically, first, all LED lamps are evenly divided into a number of backlight blocks (LED blocks), and a picture to be displayed is divided into a number of image blocks correspondingly, the backlight blocks and the image blocks being in one-to-one correspondence; then outgoing light brightnesses of the backlight blocks are calculated based on display brightnesses of pixels in the image blocks by using a preset dynamic dimming algorithm; next, corresponding drive currents, namely drive currents corresponding to the backlight blocks, are looked up based on the calculated backlight brightnesses; and finally, the corresponding drive currents are outputted to the backlight blocks, so that the backlight blocks output corresponding outgoing light brightnesses.
With the existing local dimming method, a backlight block corresponding to a highlight portion of the picture to be displayed can exhibit relatively high outgoing light brightness, while a backlight block corresponding to a dark portion of the picture to be displayed can exhibit relatively low outgoing light brightness or even be turned off. In this case, the power consumption of a backlight source can be effectively reduced since the outgoing light brightnesses of part of the backlight blocks are lowered.
Although the existing backlight adjustment technology can reduce the power consumption of the backlight source, obvious bright-dark layering is prone to occur in an area on the backlight source corresponding to an intersection between the backlight block with a high outgoing brightness and the backlight block with a low outgoing brightness, which can affect a user's experience.